A memory device having three-dimensional structure is proposed. In the memory device, memory holes are formed in a stacked body including a plurality of electrode layers. A charge storage film and a semiconductor film extending in a staking direction of the stacked body are provided in the memory holes.
The memory holes are formed by e.g. anisotropic dry etching. When the aspect ratios of the memory holes are higher, it becomes difficult to control the diameters of the memory holes to be uniform in the depth direction. The differences in diameter of the memory holes lead to variations in memory cell characteristics.